This application is based upon and claims the benefit of priority from the prior Japanese Patent Applications No. 2001-067304, filed Mar. 9, 2001; and No. 2001-067305, filed Mar. 9, 2001, the entire contents of both of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a processing system which includes a laser processing system, a film deposition system and a pattern forming system in order to form an electronic device such as a semiconductor device.
2. Description of the Related Art
Resist coating, exposure and development are carried out on a semiconductor wafer in a lithography process of manufacturing a semiconductor device. In this lithography process, an alignment between an upper layer pattern and a lower layer pattern are accomplished to carry out the pattern exposure. Generally, an exposure apparatus is employed for this pattern exposure.
The exposure apparatus is provided with an alignment mechanism for detecting a position of the lower layer pattern. The alignment mechanism computes a position for exposing the upper layer pattern by detecting a position of an alignment mark disposed on the lower layer pattern. After the lithography process is finished, an alignment error detection is carried out for detecting the alignment error between the lower layer and the upper layer pattern. For the alignment error detection, an error detection mark is disposed. The alignment error detector measures the position of this error detection mark. Generally, the alignment detection and the error detection are carried out by optical position detection. The alignment mark and the error detecting mark may be sometimes provided each having low-transparency film, which are formed over those films, in order to pass the same processing steps as the semiconductor integrated circuit. Thus, if the low-transparency film is formed on the mark, the alignment mark and the error detection mark are difficult to recognize. For the reason, it is required for removing that low-transparency film formed over the alignment mark.
However, a conventional laser processing apparatus cannot remove the low-transparency film on the mark accurately, so that a region not desired to be removed may be sometimes removed, which is a problem to be solved.
Further, deterioration of the alignment accuracy upon exposure is a problem in the aforementioned lithography process. This is because a resist is formed asymmetrically due to an unevenness or roughness of the underlying layer. To eliminate this problem, Jpn. Pat. Appln. KOKAI Publication Nos. 62-252136, 63-117421 and 2-298017 have disclosed, which describe means for processing the resist film such as a light sensitive film with a laser beam.
However, the aforementioned problem has been eliminated because the processing surface (mainly SiO2 film) is planarized by mean of chemical mechanical polishing (CMP) in recent years. However, if patterning is carried out on a resist film formed on the substrate, there is produced such a problem that pattern deterioration occurs accompanied by standing wave. The standing wave is produced by an interference between a light reflected from a reflecting surface of metal or polysilicon after exposure light passes through the resist film and then oxide film. Thus, a reflection protecting film for preventing reflection of the exposure light from the underlying layer is used under the resist film in order to prevent such standing wave which may be generated in the resist film. However, because the reflection protecting film is formed, it becomes difficult that observation of the alignment mark necessary for detecting the positional information of the pattern on a processing substrate upon exposure. Particularly, alignment performed through a mask and lens using the exposure light as alignment light, which system has been adopted recently in order to achieve high accuracy positional information detection, has such a problem that the alignment mark cannot be seen because of the reflection protecting film. Jpn. Pat. Appln. KOKAI Publication No. 2001-15407 has disclosed a method of processing and removing this reflection protecting film with laser.
Removal of an organic film with laser beam has been disclosed in Jpn. Pat. Appln. KOKAI Publication Nos. 62-252136, 63-117421, 2-298017, 5-3143, 5-198496, 7-161623, and 10-113779 and the like. According to all these disclosed arts, the organic film is evaporated by irradiating a processing film directly with laser beam. There is such a problem that foreign materials (unburnt organic film residue) generated at that time exist diffusingly in the vicinity of the processing region thereby producing a defect and failure. Further, there is another problem that a processing portion boundary is swollen by heat generated upon the laser processing.
The conventional laser processing apparatus is incapable of removing opaque film on the mark accurately. Consequently, a region not desired to be removed is also removed or when removing organic film or inorganic film existing on a region containing the alignment mark by irradiation of the energy beam such as the laser beam, foreign materials are scattered around the removal region thereby inducing the defect or failure. Therefore, there have been demanded a laser processing apparatus capable of removing only the removal region when irradiating a substrate to be processed with a laser beam and a laser processing system capable of suppressing damage in the vicinity of an energy beam irradiation region on a surface of the substrate to reduce generation of scattered substance accompanied by irradiation with the energy beam.
According to an aspect of the present invention, there is provided a laser processing apparatus, which comprises a laser oscillator for producing a laser beam for selectively removing part of a substrate to be processed; a scanning system for applying the laser beam to an arbitrary position of the substrate; and incident means for applying the laser beam to the substrate substantially at right angle.
According to another aspect of the present invention, there is provided a film deposition system, which comprises a carrier station for holding one or more substrates to be processed; coating film forming means for supplying a coating film forming chemical containing a solvent to a main surface of the substrate to form a coating film on the main surface; removing the solvent contained in the coating film to form a film on the main surface; laser processing means for applying an energy beam to the main surface from an energy irradiation device to remove selectively at least part of the film from the main surface; and carrying means, connected to the carrier station, coating film forming means, coating film forming means and laser processing means, for carrying in and out the substrate.
According to still another aspect of the present invention, there is provided a pattern forming system, which comprises a carrier station for holding one or more substrate to be processed the substrate having an alignment mark in a main surface thereof; first film forming means for forming a first thin film on the main surface; first coating film forming means for forming a coating film on the first thin film by supplying a coating film forming chemical containing both a sensitive material and a solvent to the main surface; second coating film forming means for forming a light sensitive thin film by removing the solvent contained in the coating film formed by the first coating film forming means; laser processing means for selectively removing at least part of the light sensitive thin film and the first thin film formed on the substrate by irradiating the main surface with an energy beam from an energy irradiation device; latent image forming means for detecting a position of an alignment mark on the main surface, thereby forming a latent image in the light sensitive thin film based on positional information of the detected alignment mark; light sensitive thin film pattern forming means for forming a light sensitive thin film pattern by applying one of an etching solution and an etching gas to a surface of the light sensitive thin film to remove at least part of the light sensitive thin film selectively; and carrying means, connected to the carrier station, the coating thin film forming means, the coating thin film forming means and laser processing means, for carrying the substrate.
According to a further aspect of the present invention, there is provided a method of manufacturing a semiconductor device, which comprises forming a first thin film on a main surface of a semiconductor substrate having an alignment mark; applying a first energy beam to the first thin film provided on a region containing the alignment mark to selectively remove part of the first thin film; supplying a chemical containing both a light sensitive material and a solvent onto the first thin film to provide a coating film thereon; removing the solvent contained in the coating film to form a light sensitive thin film; carrying the semiconductor substrate to latent image forming means and irradiating the positioning mark with a reference beam through a region in which the first thin film is selectively removed, thereby to recognize a position of the alignment mark; irradiating a predetermined position on the light sensitive thin film with a second energy beam based on the position of the recognized alignment mark to form a latent image on the light sensitive thin film; and forming a light sensitive thin film pattern by removing at least part of the light sensitive thin film based on the latent image formed on the light sensitive thin film, wherein upon irradiating the first energy beam, liquid is supplied to at least a region irradiated with first energy beam.
According to a still further aspect of the present invention, there is provided a method of manufacturing a semiconductor device, which comprises forming a first thin film on a main surface of a semiconductor substrate having an alignment mark; supplying a chemical containing a light sensitive material and a solvent to the first thin film to form a coating film on the first thin film; forming a light sensitive film by removing the solvent contained in the coating film to provide a light sensitive film thereon; applying a first energy beam to the light sensitive film provided on a region containing the alignment mark, thereby to selectively remove the light sensitive film and part of the first thin film; recognizing a position of the alignment mark by irradiating the alignment mark with the reference light through the region in which the first thin film is selectively removed; forming a latent image on the light sensitive film by irradiating a predetermined position of the light sensitive film with a second energy beam based on the position of the recognized alignment mark; and forming a light sensitive film pattern by selectively removing part of the light sensitive thin film based on the latent image formed on the light sensitive film, wherein upon irradiating the first energy beam, a liquid is supplied to at least a region irradiated with the first energy beam.
According to a yet still further aspect of the present invention, there is provided a method of manufacturing a semiconductor device, which comprises forming a coating film by supplying a chemical containing a light sensitive material and a solvent onto a main surface of a semiconductor substrate having an alignment mark; forming a light sensitive thin film on the semiconductor substrate by removing the solvent contained in the coating film; removing selectively part of the light sensitive thin film by irradiating the light sensitive thin film on a region containing the alignment mark with a first energy beam; carrying the semiconductor substrate to latent image forming means to irradiate the alignment mark with a reference light through the region in which the light sensitive thin film is selectively removed, thereby recognizing a position of the alignment mark; forming a latent image on the light sensitive thin film by irradiating a predetermined position of the light sensitive thin film with a second energy beam based on the position of the recognized alignment mark; and forming a thin film pattern by removing selectively the thin film based on the latent image formed in the light sensitive thin film, wherein upon irradiating the first energy beam, a liquid is supplied to a region irradiated with the first energy beam.